High Resolving\nPower Electrospray Ionization Ion Mobility\nSpectrometer Based on Fourier Deconvolution Multiplexing

The resolving power of the drift\ntube ion mobility spectrometry\n(IMS) is mainly dependent on the drift length, the drift voltage,\nthe pulse width of an ion gate, and the pressure inside the drift\ntube. Electrospray ionization (ESI)-IMS is a highly sensitive and\nreliable technique for the detection and analysis of nonvolatile compounds,\nand high resolving power is necessary to separate structurally similar\ncompounds. To improve the analytical performance of atmospheric pressure\nESI-IMS, the Fourier deconvolution (FD) multiplexing technique is\ninvestigated as an effective and convenient means to improve the resolving\npower as well as the signal-to-noise ratio. By reducing the equivalent\nion gate opening width to 5 μs using a typical Tyndall–Powell\nion shutter, a high resolving power <i>R</i><sub>P</sub> up to 170 can be achieved with a drift length of 12 cm and a drift\nvoltage of 10 kV. Rhodamine 6G (R6G), sodium dodecyl sulfate (SDS),\nmethacycline, oxytetracycline, and ractopamine were evaluated using\nthe FD-ESI-IMS, and mixtures with similar ion mobility can be well\nseparated without prolonging the drift length.